The present invention relates to power modules and, more particularly, to integrated power modules and method for forming the same.
A power conversion device, such as a three phase uninterruptible power supply (UPS), may include multiple power conversion circuits. For example, an online UPS may include a rectifier that is used to rectify an input AC voltage to generate a DC voltage and an inverter that generates an AC voltage from this DC voltage. The UPS may also include additional power conversion circuits, such as battery charger and/or converter circuits.
Such power conversion circuits typically include a variety of printed circuit board (PCB) mounted components such as inductors, current sensors insulated gate bipolar transistor (IGBT) bridge circuits. Packaged multi-transistor devices have been developed for such applications. For example, “six pack” devices are offered that include three IGBT half-bridges mounted on a common heat sink and encased in a molded housing. Passive devices, such as inductors or capacitors, may be coupled to pins of such a device to form a rectifier, inverter, or other power conversion circuit.
The inductors are generally heavy devices made from coiled wire. As such, it may be difficult to mount the inductor on the PCB including the other circuit components. Typically, the separately mounted inductors are electrically coupled to the PCB with the other circuit components using a series of bus bars, wires and connectors. The inductors may be grouped and/or packaged in a mounting arrangement separate from the mounting of the PCB with the other circuit components. Such an arrangement typically results in the use of relatively large enclosures for the power conversion circuits. The enclosure must also generally provide cooling to various included heat generating elements, such as the IGBTs and the inductors, which cooling arrangement may include heat sinks, cooling fans and the like.